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Walking

These paths are well defined at first and you can get a taste of the reserve and enjoy the views by following them for a short way or try our waymarked Tram and Train Trail.

The paths have some short steep stretches and several stiles and kissing gates.

If you wish to walk further, we strongly recommend that you take a map.

Please stay on the paths because the ground is very rough and uneven and there are deep sink holes throughout the reserve.

Tram and Train Trail

1½ miles, 2.3km or 2½ miles, 3.6km with railway line, moderate

Follow this short waymarked walk around the reserve – look for lime-loving wildflowers in late spring and, at any time of year, discover the remains of a former hive of industry. You’ll find a tramway, a railway line, lime kilns and a brick works.

Penwyllt – Craig-y-nos

4½ miles, 7.2km, difficult circular walk

A moderate walk suitable for families with older children (8+) along bridleways and old tramroads. This walk provides an insight into the fascinating lives of the men and women who lived and worked in Penwyllt.

Closures and diversions

Sometimes we need to close or divert trails for your safety whilst we undertake maintenance work or forest operations

Occasionally we may have to close a site in extreme weather, such as high winds or snow and ice due to the risk of injury to visitors or staff

Please always follow any instructions onsite and make sure you follow any temporary diversion signs in place

How to get here

Ogof Ffynnon Ddu National Nature Reserve is six miles north of Ystradgynlais.

The OS grid reference is SN 866 154.

Car parking is free of charge.

Directions

Take the A4067 from Ystradgynlais to Abercraf and Pen y Cae. Continue through Pen y Cae and turn right down a minor road signposted to Penwyllt. Follow brown and white tourist signs over river and left at T-junction. Go past disused quarry along track to car park.